Retrieving tool for well bores



Nov. 25, i947. c. R. ATHY 2,431,351

RETRIEVING TOOL FOR WELL BORES Filed April e, 1945 Patented Nov. 25, 1947 UNITD STATES PATENT OFFICE RETRIEVING TOOL FOR WELL BORES Clifford R. Athy, Columbus, Ohio, aspsgnor to Internatonal Derrick and Equipment Company, Columbus, Ohio, a corporation of Ohio Application April 6, 1945, Serial No. 586,942

2 Claims.

' the like that the drilling bits employed in the operation will break, thus leaving fragments of hardened steel in a loose or free state at the bottom of the well bore. To continue further drilling of the well, it is necessary to remove such fragments, since otherwise they would cause damage to other drills contacting therewith. At present the well-drilling art employs quite generally, under conditions of the nature specified, mechanically operating jaw devices which are cable suspended and, through manipulation, are adapted to grip loose solid bodies or objects resting on the bottom of a well bore to admit of the lifting and removal of the same from the bore.

Such mechanical gripping tools, however, cannot be manipulated with any appreciable degree of certainty from the top of a well bore. When it is considered that in oil well drilling particularly, a well bore may possess a depth measured in thousands of feet, the difficulties in manipulating a mechanical gripping tool to cause it to grip the object sought to be retrieved, disposed many feet below and entirely out of sight, are manifest. Their use is entirely a hit or miss in character. If fortunate in gripping the body sought, the operation may be carried out with reasonable promptness, but it is not uncommon for such an operation to require many hours, even days, before the object sought is successfully removed, and, of course, during the operation, well drilling is entirely stopped and the drilling crew and equipment remain idle with accompanying high cost.

Therefore, it is an object of the present invention to provide an improved retrieving tool for rendering the operation of removing loose drilling obstructing ferrous bodies from the bottom of a well bore, and doing so in a more certain and expeditious manner.

Another object is to provide a tool for the pur 'l nales wm not interfere with the contacting df the magnetic tool with the metal objects sought to be removed.

With these and other objects in view, the invention consists in the novel features of con\` struction, combinations of elements and arrangements of parts hereinafter more fully described and pointed out in the appended claims.

'In the drawings:

i Fig. 1 is a vertical sectional view taken through the improved magnetic retrieving tool comprising the present invention; I

Fig. 2 is a similar view taken on a plane perpendicular to that of Fig. l;

Fig. 3 is a bottom plan view;

Fig. 4 is a sectional view on the line I-I of Fig. 2 i

Fig. 5 is a perspective view of one of the magnet halves. t l y Referringv to the drawings, the numeral 5 designates my improved magnetic retrieving tool in its entirety. In the specific embodiment thereof illustrated, the same is formed to provide a steel head 6, which is formed internally with a conical and threaded socket 1, the latter being adapted for the reception of the correspondingly threaded lower end of a string of drill pipe 8, extending to the top of a well bore in which the tool is used, and through which tubing water, or other liquid, is passed.

The lower end of the head is angularly shouldered, as at 9, and formed with an externally threaded extension I0 of reduced diameter. Adapted for engagement with the threads of the extension I0 are internal threads provided at the upper end of a tubular brass casing II. The socket 'I terminates at its lower end in a bore I2 in which is positioned and firmly secured the tubular upper end of an inverted Y-shaped water-discharging nozzle I3, formed of a nonmagnetic material, preferably of austenitic stainless steel, said nozzle being disposed within the y confines ofthe casing I I.

'j Positioned in the tool between the casing II and the nozzle I3, and arranged below the head 5', is a permanent magnet IIa which may be an iron alloy containing, aluminum, nickel and cobalt. However, it will be understood that I may use any other suitable metal or metals having the desired magnetic properties, The magnet is formed in two halves, in order that it may be placed around the nozzle I3 and to be substantially coextensive therewith. The lower end of the casing is closed by a pair of outer, segmental steel plates II-Il and an intermediate brass bar I5, the outer edges of the plates I4 and the bar I5 being brazed or otherwise permanently attached to the adjacent lower edge regions of the casing I I. The bar I5 is provided with a pair of water outlets I 6, which are disposed in registration with the lower diverging ends of the nozzle I3.

In the use and operation of the tool, when it is desired to retrieve a loose fragment of steel or the like, such as a. rock bit cutter, or part thereof, from the bottom of a well bore, a string of drill pipe having the retrieving tool on the bottom thereof is lowered until the retrieving tool is positioned onor immediately adjacent to the bottom of the well bore. Fluid is then passed through the tubingand issues in a divided stream through the outlet I6 in forceful jets. This produces a turbulent suspension of sand or other fine earthy particles in water so that the magnetic retrieving tool may be brought readily into attracting contact with the metal object or objects sought to be retrieved. When such contact is established, the drill pipe with .the retrieving tool and the metal object or objects attracted thereby are elevated through the use of the customary drilling rig or derrick apparatus. The operation may be quickly carried out, as compared with other standard modes of procedure and with completeassurance as to the success of the operation.

The permanent magnet has high magnetic powers, particularly when formed from the alloy described a'nd is capable of attracting and holding on the bottom of the tool metal objects weighing as much as.100 pounds. the permanent magnet is preferable over an electromagnet, since it eliminates the necessity of extending current conductors to the bottom of a well bore. The divided nozzle I3 provides for the issuance of spaced jets of iiuid under pressure from the lower end of the tool, which increases the turbulence of the mud-laden uid so that the tool readily penetrates the formations in the bottom of the well in reaching the metal to be recovered. 45

I claim:

1. A magnetic retrieving tool for well bores comprising a casing, a sectional permanent magnet mounted within said casing, means for attaching the upper end of said casing to the lower end of a fluid-supplying pipe system, and a nozzle positioned in said casing between the sections of said magnet, the upper end of said nozzle communicating with said pipe system and the lower portion of said nozzle terminating in diverging uid outlets opening to the bottom of the casing.

2. A magnetic retrieving tool for well bores comprising a casing, a sectional permanent magnet mounted within said casing, means for attaching the upper end of said casing to the lower end of a fluid-supplying pipe system, a nozzle positioned in said casing between the sections of said magnet, the upper end ot said nozzle communicating with said pipe system and the lower portion of said nozzle terminating in diverging fluid outlets opening to the bottom of the casing, and a closure for the bottom of said casing embodying a pair of outer plate sections of magnetic materials and an intervening bar section of nonmagnetic material, said intermediate bar section being formed with openings registering with the diverging outlets of said nozzle.

' CLIFFORD R. ATHY.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS 

